What it means
The minimum stop calibration of throttle position sensor B does not match the learned reference during ECU self-test. Sensor B is the redundant channel used to cross-check sensor A.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
- The engine or gearbox may go into limp mode
How it works
Throttle position sensor B is a separate position signal the engine control module compares with sensor A for plausibility. P2116 sets when the module’s self-check finds sensor B’s reading at the minimum stop outside its learned range, even if sensor A appears normal.
Common causes
Most likely first.
- Carbon deposits affecting throttle motion
- Internal sensor B fault
Symptoms
- Check engine light on
- Reduced throttle response, possible limp mode
- Hesitation or surging
- Idle too high or too low
How to diagnose it
- Read freeze-frame data and compare sensor B’s closed-throttle reading with sensor A and other position channels to identify a B-specific mismatch.
- Inspect the throttle body for deposits that prevent full closure, then examine sensor B’s connector and wiring for corrosion, looseness, or damage.
- With the ignition on and engine off, watch sensors A and B live while moving the throttle; both should change smoothly and show a plausible minimum position.
- Test sensor B’s reference, ground, and signal circuits against the manufacturer’s specification, checking for an open, short, or poor connection.
- If the plate moves freely and wiring tests pass, evaluate sensor B and the throttle actuator, then perform any manufacturer-specified relearn.
Common fixes
- Repair damaged or poorly connected sensor B wiring or connector pins.
- Clean deposits that keep the throttle plate from reaching its minimum stop.
- Replace the sensor B element or throttle body if its signal fails testing.
- Repair the throttle actuator or perform the required relearn if the plate cannot return to its learned minimum.
Can I keep driving?
A sensor B minimum-stop fault can trigger reduced power or limp mode, so avoid overtaking and situations that require quick acceleration. If throttle response is erratic or restricted, stop driving when safe.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.